1. Field of the Invention
The present invention relates generally to manufacture of heads for data storage devices and more specifically to a write head with first and second pole tips which are self aligned during the manufacturing process.
2. Description of the Prior Art
A computer disk drive stores and retrieves data by positioning a magnetic read/write head over a rotating magnetic data storage disk. The head, or heads, which are typically arranged in stacks, read from or write data to concentric data tracks defined on surface of the disks which are also typically arranged in stacks. The heads are included in structures called “sliders” into which the read/write sensors are imbedded during fabrication. The goal in recent years is to increase the amount of data that can be stored on each hard disk. If data tracks can be made narrower, more tracks will fit on a disk surface, and more data can be stored on a given disk. The width of the tracks depends on the width of the poles in read/write head used, and in recent years, track widths have decreased as the size of read/write heads have become progressively smaller. This decrease in track width has allowed for dramatic increases in the recording density and volume of data storage of disks.
The type of head for writing data is generally configured with two poles separated by a gap layer of non-magnetic material. These are generally referred to as the first pole or P1 and the second pole P2, with a non-magnetic gap layer between them. Recently, a design has come into use in which the P1 pole is configured with a protrusion or protrusion, which is sometimes referred to as a P1P or P1 Protrusion. This protrusion or protrusion enables magnetic flux to be channeled and concentrated to a smaller area. In order to maintain the advantage of this narrowed P1P structure in concentrating flux lines, it is advantageous for the P2 pole to be similarly narrow at the pole tip. The two pole tips of P1P ands P2 must also be in precise alignment in order for good performance of the write head. Thus, there is the difficulty of aligning two components whose dimensions may be on the order of 0.4 μm (0.4×10−6 meters) in width. Obviously, aligning two independently fabricated elements of such small magnitude would be a difficult task, and it would be much preferable to have the poles “self-aligned” or fabricated in proper registration with each other to begin with.
Thus, there is a great need for a write head having self-aligned poles and for a method of manufacture which produces this type of write head.